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71.
1引言2006年12月11日是我国正式加入世界贸易组织五周年,也是开放基础电信业务二周年。外资运营商进入中国市场的步伐也有加快的迹象。澳大利亚电讯(亚洲)总裁、澳大利亚电讯(中国)CEO贝裕铭日前表示,澳大利亚电讯要看3G(第三代移动通信)牌照发给哪家运营商,谁来做相关的3G业务,再决定战略性的合作。西班牙运营商Telefonica、新加坡电信、英国沃达丰相关负责人也表达了同样的态度。 相似文献
72.
蠕变过程中碳化物形貌,类型,数量和分布状态的变化直接影响着材料的高温性能,因而在材料的蠕变得到了广泛的重视,介绍了一种在碳膜萃取复型样品上利用H-800透射电子显微镜的双倾样品台进行了大角度倾转,来观察碳化物形貌并鉴定其类型的试验方法。 相似文献
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我们研制了一种8毫米波变张角、半径突变的多模圆锥馈源。计算出其模比并推导出其辐射方向图公式;给出其在两个主平面——E平面与H平面上的辐射方向图和波束场分布特性的测试结果以及电压驻波比VSWR的测量结果;同时给出频带和旁瓣特性。分析与测试共同表明,在34.5GHz~37GHz频带里,该多模馈源的辐射图在大于24dB范围内获得幅度等化且不出现旁瓣,因此具有一定的应用价值。 相似文献
75.
通过对热轧左旋带肋钢筋(HRBL600)的质量特性分析,制定了热轧左旋带肋钢筋的化学成分,孔型设计方案和生产工艺。生产实践证明:该产品开发获得成功,产品质量达到标准要求。 相似文献
76.
过去的几年中,亚洲尤其是中国,已经成为一个酶制剂用量快速增长的市场.中国食品工业的发展从酶生物技术中获益颇多,酶生物技术已成为这种加工助剂为其中的食品工业带来了重大的创新中不可或缺、革新与安全的加工手段之一. 相似文献
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E Co?ffier M Girard F Barré-Sinoussi B Meignier E Muchmore PN Fultz C LeClerc 《Canadian Metallurgical Quarterly》1998,14(12):1023-1034
The fine specificity of the anti-V3 antibody responses induced in chimpanzees immunized by various human immunodeficiency type 1 (HIV-1) candidate vaccines and challenged by heterologous strains of HIV-1 was analyzed by enzyme-linked immunosorbent assay (ELISA) and Pepscan epitope mapping. Two chimpanzees immunized with the recombinant canarypox virus ALVAC-HIV (vCP125) expressing gp160MN and boosted with purified gp160MN/LAI alone, then with both immunogens in combination, were not protected against challenge with HIV-1 SF2. Their sera mainly recognized one epitope of the V3 loop, located in the NH2-terminal half. By contrast, immunization of two other chimpanzees with purified gp160MN/LAI and boosting with a synthetic V3MN peptide elicited a strong anti-V3 antibody response with a broader specificity directed against multiple epitopes all along the V3 loop. These chimpanzees were protected against infection by HIV-1 SF2. However, when these two chimpanzees were challenged later with a HIV-1 clade E strain virus, they became infected. We failed to detect any reactivity with the peptide of the ectodomain of gp41 of sera harvested after immunization with the various immunogens or after challenge with HIV-1 SF2 or HIV-1 90CR402. These results demonstrated that anti-V3 antibodies with a restricted fine specificity were induced in chimpanzees immunized with gp160 purified or expressed by recombinant canarypox confirming our previous results obtained in three different species (human, guinea pig and, macaque). In contrast, a boost with the V3 peptide broadened antibody responses, suggesting that the mode of presentation of the V3 loop to the immune system strongly influences the epitope specificity of the resulting antibody response. 相似文献
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LEE Hyeon-deok SON Myeong-jo OH Min-jae LEE Hyung-woo KIM Tae-wan 《中国科学:信息科学(英文版)》2012,(5):1019-1031
In early 2000,large domestic shipyards introduced shipbuilding 3D computer-aided design (CAD) to the hull production design process to define manufacturing and assembly information.The production design process accounts for most of the man-hours (M/H) of the entire design process and is closely connected to yard production because designs must take into account the production schedule of the shipyard,the current state of the dock needed to mount the ship’s block,and supply information.Therefore,many shipyards are investigating the complete automation of the production design process to reduce the M/H for designers.However,these problems are still currently unresolved,and a clear direction is needed for research on the automatic design base of manufacturing rules,batches reflecting changed building specifications,batch updates of boundary information for hull members,and management of the hull model change history to automate the production design process.In this study,a process was developed to aid production design engineers in designing a new ship’s hull block model from that of a similar ship previously built,based on AVEVA Marine.An automation system that uses the similar ship’s hull block model is proposed to reduce M/H and human errors by the production design engineer.First,scheme files holding important information were constructed in a database to automatically update hull block model modifications.Second,for batch updates,the database’s table,including building specifications and the referential integrity of a relational database were compared.In particular,this study focused on reflecting the frequent modification of building specifications and regeneration of boundary information of the adjacent panel due to changes in a specific panel.Third,the rollback function is proposed in which the database (DB) is used to return to the previously designed panels. 相似文献